1. Field of the Invention
The present invention relates to a laminarizer or arrangement for producing laminar flow, particularly for ceilings and walls of clean rooms or the like formed of filter modules. The laminarizer is suspended or held spaced from a cover supporting mechanical filters. The laminarizer is composed of rectangular frames with fabric sheets stretched onto the rectangular frames. The side members of the rectangular frames are hollow sections or angle sections which are triangular in cross-section. The fabric sheets rest against and are aligned by the surfaces of the sections facing the room.
2. Description of the Related Art
Filter modules for ceilings and walls or the like of clean rooms are already known from German Utility Model No. 87 10 781. In these filter modules, a cover carrying mechanical filters is supported by rectangular frames which are arranged at a distance from the cover. Fabric sheets are stretched onto the frames. The fabric sheets create a slight pressure increase which, in turn, has the effect that the filtered air flows in practically equal quantities through a plurality of fine meshes, so that a laminar piston-type flow is created on the outlet side.
The laminarizers formed by the rectangular frames and the fabric sheets resting on the frames have in the past already been constructed in such a way that the frames have on the outlet side only a small cross-section, so that transverse flows and turbulences are prevented which could keep any impurities which have reached the clean room in suspension.
In the known laminarizers, fabric sheets are glued together in the aligned position at the surfaces of the triangular hollow sections or angle sections facing the room. On the other hand, when these laminarizers are mounted, in front of the outlet side of the filter modules of ceilings or walls or the like of clean rooms, the gaps between the outer surfaces of adjacent rectangular frames facing each other are completely sealed or are reduced to defined passage cross-sections.
However, practical experience with laminarizers in which filter modules according to the German Utility Model No. 87 10 781 are used, has shown that in the edge zones of these laminarizers bordered by the rectangular frames as well as in the region of the gap between the frames of adjacent laminarizers, certain disturbances of the flow are created which impair the perfect formation of a laminar piston-type flow in the room.
It is, therefore, the primary object of the present invention to provide a laminarizer of the above-specified type in which not only with particularly simple means the possible flow disturbances at the outlet side are further minimized, but in which also the stability or strength of the connection between the rectangular frames and the fabric sheets is improved.